/* Micro-C Code Generatation Part for Mips */

#define EXTERN extern
#include "mc.h"

#define REGISTERS6   0

void code_init(void);
void free_register(int i);
void emit_init(void);
void emit_push(void);
void gexpr(int e1);
void g_expr(int e1);
void bexpr(int e1, char cond, int l1);
void b_expr(int e1, char cond, int l1);
void string(int e1);
void function(int e1);
void machinop(int e1);
void rindirect(int e1);
void assign(int e1);
void sassign(int e1);
void assop(int e1);
void tosop(int op);
void shift(char *op, int reg) ;
void ld_indexx(int byte, int n, char *xrn);
void st_indexx(int byte, int n, char *xrn);
void indexy(char *op, char *gvar);
void cmpdimm(int e, int csreg);
void global_table(void) ;
void local_table(void) ;
void opening(char *filename);
void closing(void);
void gen_gdecl(char *n, int gpc) ;
void jmp_label(int l);
void jmp_eq_label(int l);
void rexpr(int e1, int l1, char *s);
void jcond(int l, char cond);
void jmp(int l);
void def_label(int cslabel, int dlabel) ;
void gen_comment(char *s);
void gen_source(char *s);
void code_enter(char *name) ;
void code_leave(char *name) ;
void enter(char *name, int disp) ;
void enter_no(char *name,int disp);
void enter1(int disp) ;
void ret(void);
void emit_data(int e, int t, NMTBL *n);
void    text_mode(void);
void    data_mode(char *name);
int  get_register_var(void);
void	jump(int e1, int env);
int	lvar(int l);

int cadr(int e);
int car(int e);
int caddr(int e);
int fwdlabel(void);
void fwddef(int l);
int cadddr(int e);
int backdef(void);
int error(int n);
int size(int t);
int list3(int e1, int e2, int e3);
extern int scalar(int);
extern int reverse0(int);

#define TEXT_EMIT_MODE 0
#define DATA_EMIT_MODE 1
#define RODATA_EMIT_MODE 2

static output_mode = TEXT_EMIT_MODE;
static data_alignment = 0;

/*
         local1 <----24 local variable
                    -20  <- disp_offset
        saved register
        .mask  0...0,-8
        .fmask 0
        $fp = $sp     0
        $ip           4   <- arg_offset
          arg1        8
 */
int arg_offset = 8;
int code_arg_offset = -4;
int disp_offset = -12;
int func_disp_offset = -12;
int code_disp_offset = -4;
int size_of_int = 4;
int endian = 0;
int MAX_REGISTER=32;         /* Mipsのレジスタを32つまで使う*/
int REAL_MAX_REGISTER=32;    /* Mipsのレジスタが32つということ*/
int MAX_REGISTGER_VAR=20;    

int save_reg = 0;   /*saveされたレジスタの回数*/
int save_reg1 = 0;

static int  creg;     /* current register */
static char *crn;     /* current register name */
static int  lreg;     /* operand register */
static char *lrn;     /* operand register name */
static int  dreg;     /* temporary register */
static char *drn;     /* temporary register name */
static int  xreg;     /* pointer register */
static int  reg_sp;   /* REGister Stack-Pointer */


#define REG_00   0
#define REG_01   1
#define REG_02   2
#define REG_03   3
#define REG_04   4
#define REG_05   5
#define REG_06   6
#define REG_07   7
#define REG_08   8
#define REG_09   9
#define REG_10  10
#define REG_11  11
#define REG_12  12
#define REG_13  13
#define REG_14  14
#define REG_15  15
#define REG_16  16
#define REG_17  17
#define REG_18  18
#define REG_19  19
#define REG_20  20
#define REG_21  21
#define REG_22  22
#define REG_23  23
#define REG_24  24
#define REG_25  25
#define REG_26  26
#define REG_27  27
#define REG_28  28
#define REG_29  29
#define REG_30  30
#define REG_31  31

static char *reg_name[32]; 

/*
    creg   currrent virtual register
    lreg   operand virtual register
    dreg   spare virtual register

    rname[creg]   currrent real register
    rname[lreg]   operand real register
    rname[dreg]   spare real register

    regs[]        virtual register usage

    reg_name[rname[creg]]
 */

#define MAX_MAX 40
static int rname[MAX_MAX];
static int regs[MAX_MAX];       /* 使われているレジスタを示すフラグ */
static int reg_stack[MAX_MAX];  /* 実際のレジスタの領域 */

void
code_init(void)
{
    int i;

    if (REGISTERS6) {
	arg_offset = 8;
	func_disp_offset = -20;
	disp_offset = -20;
	size_of_int = 4;
	endian = 0;
	MAX_REGISTER=32;
    } else {
	arg_offset = 8;
	func_disp_offset = -12;
	disp_offset = -12;
	size_of_int = 4;
	endian = 0;
	MAX_REGISTER=32;
    }
    MAX_REGISTER_VAR=2;    

    reg_name[REG_00] = "$0";
    reg_name[REG_01] = "$1";
    reg_name[REG_02] = "$2";
    reg_name[REG_03] = "$3";
    reg_name[REG_04] = "$4";
    reg_name[REG_05] = "$5";
    reg_name[REG_06] = "$6";
    reg_name[REG_07] = "$7";
    reg_name[REG_08] = "$8";
    reg_name[REG_09] = "$9";
    reg_name[REG_10] = "$10";
    reg_name[REG_11] = "$11";
    reg_name[REG_12] = "$12";
    reg_name[REG_13] = "$13";
    reg_name[REG_14] = "$14";
    reg_name[REG_15] = "$15";
    reg_name[REG_16] = "$16";
    reg_name[REG_17] = "$17";
    reg_name[REG_18] = "$18";
    reg_name[REG_19] = "$19";
    reg_name[REG_20] = "$20";
    reg_name[REG_21] = "$21";
    reg_name[REG_22] = "$22";
    reg_name[REG_23] = "$23";
    reg_name[REG_24] = "$24";
    reg_name[REG_25] = "$25";
    reg_name[REG_26] = "$26";
    reg_name[REG_27] = "$27";
    reg_name[REG_28] = "$28";
    reg_name[REG_29] = "$29";
    reg_name[REG_30] = "$30";
    reg_name[REG_31] = "$31";

}

char *
register_name(int i)
{
    return reg_name[rname[i]];
}

int 
get_register(void)
{    /* 使われていないレジスタを調べる */
    int i;
    for(i=0;i<MAX_REGISTER;i++) {
	if (! regs[i]) {    /* 使われていないなら */
	    regs[i]=1;      /* そのレジスタを使うことを宣言し */
	    return i;       /* その場所を表す番号を返す */
	}
    }

    return -1;    /* 空いている場所がないなら、それを表す -1 を返す */
}

void 
free_register(int i) {    /* いらなくなったレジスタを開放 */
    regs[i]=0;
}

int
register_full(void)
{
    int i;
    for(i=0;i<MAX_REGISTER;i++) {
	if (! regs[i]) { 
	    return 0;  
	}
    }
    return 1;    
}

void 
gexpr_init(void)
{
    int i;
    while(reg_sp > 0) {
	free_register(reg_stack[--reg_sp]);
    }
    text_mode();
}

void 
emit_init(void)
{
    int i;
    for(i=0;i<REAL_MAX_REGISTER;i++) regs[i]=0;
    for(i=0;i<REAL_MAX_REGISTER;i++) rname[i]=i;
    regs[REG_00] = 1;   /* reserved */
    regs[REG_01] = 1;   /* reserved */
    regs[REG_02] = 1;   /* $v0 */
    regs[REG_03] = 1;   /* $v1 */
    regs[REG_28] = 1;   /* reserved */
    regs[REG_29] = 1;   /* reserved */
    regs[REG_30] = 1;   /* reserved */
    regs[REG_31] = 1;   /* reserved */
    creg = get_register();
    crn = reg_name[rname[creg]];
    dreg = get_register();
    drn = reg_name[rname[dreg]];
    reg_sp = 0;
    text_mode();
}

void 
set_crn(int i)
{
    creg = i;
    crn = reg_name[rname[creg]];
}

void 
set_drn(int i)
{
    dreg = i;
    drn = reg_name[rname[dreg]];
}

int
virtual(int real)
{
    int real_v,i;
    real_v = -1;
    for(i=0;i<MAX_REGISTER;i++) {
	if (rname[i]==real) {
	    real_v=i;
	    break;
	}
    }
    if (real_v == -1)
	error(-1);
    return real_v;
}

void 
use_register(int virt, int real, int move)
{
    int real_v;
    char *move_op,*a,*b;
    if (rname[virt]==real)
	return;
    real_v = virtual(real);
    if (move || regs[real_v]) {
	if(regs[real_v]) {
	    a=reg_name[real];
	    b=reg_name[rname[virt]];
	    printf("\txor \t%s,%s,%s\n",a,a,b);
	    printf("\txor \t%s,%s,%s\n",b,a,b);
	    printf("\txor \t%s,%s,%s\n",a,a,b);
	} else {
	   printf("\tmove \t%s,%s\n",reg_name[real],reg_name[rname[virt]]);
	}
    } 
    rname[real_v] = rname[virt];
    rname[virt] = real; 
    crn = reg_name[rname[creg]];
    drn = reg_name[rname[dreg]];
    lrn = reg_name[rname[lreg]];

    save_reg++;
}

int 
pop_register(void)
{     /* レジスタから値を取り出す */
    int i,j;

    j = creg;
    i = reg_stack[--reg_sp];

    if(i<0) {
	return i;
    } else {
	free_register(i);
	lreg = i;
	lrn = reg_name[rname[lreg]];
	regs[i]=0;
	return lreg;
    }
}

int
stack_used(void) {
    return reg_stack[--reg_sp]<0;
}

void 
emit_push(void)
{
    int new_reg;
    new_reg = get_register();
    if(new_reg<0) {                     /* もうレジスタがない */
	reg_stack[reg_sp++] =  -1;
	printf("\tsubu $sp,$sp,%d\n",size_of_int);
	printf("\tsw \t%s,0($sp)\n",crn);
    } else {
	reg_stack[reg_sp++] = creg;     /* push するかわりにレジスタを使う */
	set_crn(new_reg);
    }
}

char *
emit_pop(int type)
{
    char *xrn;
    if (pop_register()==-1) {
	printf("\tlw %s,0($sp)\n",drn);
	printf("\taddu $sp,$sp,%d\n",size_of_int);
	xrn = drn;
	xreg = dreg;
    } else {
	xrn = lrn;
	xreg = lreg;
    }
    return xrn;
}

int
get_register_var(void)
{
    int i;
    for(i=REG_05;i<REG_31;i++) {
	if (! regs[i]) {    /* 使われていないなら */
	    regs[i]=1;      /* そのレジスタを使うことを宣言し */
	    return i;       /* その場所を表す番号を返す */
	}
    }
    return -1;
}

void
gexpr(int e1)
{
    gexpr_init();
    g_expr(e1);
    csvalue = rname[creg]; /* for siwtch value */
}

void
g_expr(int e1)
{
    int e2,e3,e4;
    char *xrn;
    NMTBL *n;

    if (chk) return;
    e2 = cadr(e1);
    switch (car(e1)){
    case GVAR:   
	printf("\tla\t%s,%s\n",crn,caddr(e1));
	return;
    case RGVAR:
	printf("\tlw\t%s,%s\n",crn,caddr(e1));
	return;
    case CRGVAR:
	printf("\tlb\t%s,%s\n",crn,caddr(e1));
	return;
    case LVAR:
	printf("\taddu\t%s,$fp,%d\n",crn,lvar(e2));
	return;
    case REGISTER:
	/* this is of course redundant... */
	printf("\tmove\t%s,%s\n",crn,register_name(e2));
	return;
    case RLVAR:
	printf("\tlw\t%s,%d($fp)\n",crn,lvar(e2));
	return;
    case CRLVAR:
	printf("\tlb\t%s,%d($fp)\n",crn,lvar(e2));
	return;
    case FNAME:
	printf("\tla\t%s,%s\n",crn,((NMTBL *)e2)->nm);
	return;
    case CONST:  /* 代入する値が0でも特別な処理はしない */
	printf("\tli\t%s,%d\n",crn,e2);
	return;
    case STRING:
	string(e1);
	return;
    case FUNCTION:
	function(e1);
	return;
    case CODE:
	jump(e2,caddr(e1));
	return;
    case INDIRECT:
	g_expr(e2);
	return;
    case RINDIRECT: case CRINDIRECT:
	rindirect(e1);
	return;
    case ADDRESS:
	g_expr(e2);
	return;
    case MINUS:  /* レジスタに対し、引き算を実行すれば実現可能 */
	g_expr(e2);
	printf("\tsubu\t%s,$0,%s\n",crn,crn);
	return;
    case BNOT:   /* ~ */
	g_expr(e2);
	/* use_data_reg(creg,1); */
	printf("\tnor\t%s,$0,%s\n",crn,crn);
	return;
    case LNOT:   /* !  */
	g_expr(e2);
	/*use_data_reg(creg,1);*/
	printf("\txori\t%s,%s,0x0000\n",drn,crn);
	printf("\tsltu\t%s,%s,1\n",crn,drn);
	return;
    case PREINC:/* ++q */
	if (car(e2)==REGISTER) {
	    printf("\taddu \t%s,%s,%d\n",register_name(cadr(e2)),register_name(cadr(e2)),caddr(e1));
	    return;
	} 
	g_expr(e2);
	printf("\taddu \t%s,%s,%d\n",crn,crn,caddr(e1));
	return;
    case POSTINC:/* p++ */
	if (car(e2)==REGISTER) {
	    printf("\taddu \t%s,%s,%d\n",register_name(cadr(e2)),register_name(cadr(e2)),caddr(e1));
	    return;
	} 
	g_expr(e2);
	emit_push();  
    /* in case of register full we should copy crn to drn */
	xrn = emit_pop(0);
	printf("\taddu \t%s,%s,%d\n",crn,xrn,caddr(e1));
	return;
    case CPOSTINC:
	/*   char *p; *p++ */
	if (car(e2)==REGISTER) {
            printf("\tmove\t%s,%s\n",crn,register_name(cadr(e2)));
            printf("\taddu\t%s,%s,%d\n",register_name(cadr(e2)),register_name(cadr(e2)),caddr(e1));
	    return;
	} 
	g_expr(e2);
	emit_push(); /* in case of register full we should copy crn to drn */
	xrn = emit_pop(0);
	printf("\tmovsbl (%s),%s\n",xrn,crn);
	printf("\tincl (%s)\n",xrn);
	return;
    case CPREINC: /* char *p; *++p */
	if (car(e2)==REGISTER) {
            printf("\taddu\t%s,%s,%d\n",register_name(cadr(e2)),register_name(cadr(e2)),caddr(e1));
            printf("\tmove\t%s,%s\n",crn,register_name(cadr(e2)));
	    return;
	} 
	g_expr(e2);
        printf("\tincl (%s)\n",crn);
        printf("\tmovsbl (%s),%s\n",crn,crn);
	return;
    case CPOSTDEC:/* char *p; *p-- */
	if (car(e2)==REGISTER) {
	    printf("\tmove\t%s,%s\n",crn,register_name(cadr(e2)));
	    printf("\tsubu\t%s,%s,1\n",register_name(cadr(e2)),register_name(cadr(e2)));
	    return;
	} 
	g_expr(e2);
	printf("\tmovsbl (%s),%s\n",crn,crn);
	printf("\tdecl (%s)\n",crn);
	return;
    case CPREDEC:/* char *p; *--p */
	if (car(e2)==REGISTER) {
	    printf("\tdecl %s\n",register_name(cadr(e2)));
	    printf("\tmove\t%s,%s\n",crn,register_name(cadr(e2)));
	    return;
	} 
	g_expr(e2);
	emit_push();
	xrn = emit_pop(0);
	printf("\tdecl (%s)\n",xrn);
	printf("\tmovsbl (%s),%s\n",xrn,crn);
	return;
    case MUL: case UMUL:
    case DIV: case UDIV:	   
    case MOD: case UMOD:
    case LSHIFT: case ULSHIFT: case RSHIFT: case URSHIFT:
    case ADD: case SUB: case BAND: case EOR: case BOR:
	machinop(e1);
	return;
    case COND:
	e2=fwdlabel();
	b_expr(cadr(e1),0,e2);
	g_expr(caddr(e1));
	e4 = rname[creg];
	jmp(e3=fwdlabel());
	fwddef(e2);
	g_expr(cadddr(e1));
	use_register(creg,e4,1);
	fwddef(e3);
	return;
    case STASS: 
	sassign(e1);
	return;
    case ASS: case CASS:
	assign(e1);
	return;
    case ASSOP: case CASSOP:
	assop(e1);
	return;
    case COMMA:
	g_expr(e2);
	g_expr(caddr(e1));
	return;
    case RETURN:
	n = (NMTBL *)e2;
	if (retcont==0)
	    retcont=fwdlabel();
	printf("\tla\t%s,$L%d\n",crn,retcont);
	return;
    case ENVIRONMENT:
	printf("\tmove\t%s,$fp\n",crn);
	return;
    default:
	b_expr(e1,1,e2=fwdlabel());  /* including > < ... */
	/*printf("\txor \t%s,%s\n",crn,crn);*/
	jmp(e3=fwdlabel());
	fwddef(e2);
	printf("\tli \t%s,%d\n",crn,lvar(e2));
	fwddef(e3);
    }
}

void
bexpr(int e1, char cond, int l1)
{
    gexpr_init();
    b_expr(e1,cond,l1);
}

void
b_expr(int e1, char cond, int l1)
{
    int e2,l2;
    if (chk) return;
    e2=cadr(e1);
    switch(car(e1)) {
    case LNOT:
	b_expr(e2,!cond,l1);
	return;
    case GT:
	/*rexpr(e1,l1,cond?"bg":"ble");*/
	return;
    case UGT:
	/*rexpr(e1,l1,cond?"ba":"bbe");*/
	return;
    case GE:
	/*rexpr(e1,l1,cond?"bge":"bl");*/
	return;
    case UGE:
	/*rexpr(e1,l1,cond?"bae":"bb");*/
	return;
    case LT:
	/*rexpr(e1,l1,cond?"bl":"bge");*/
	return;
    case ULT:
	/*rexpr(e1,l1,cond?"bb":"bae");*/
	return;
    case LE:
	/*rexpr(e1,l1,cond?"ble":"bg");*/
	return;
    case ULE:
	/*rexpr(e1,l1,cond?"bbe":"ba");*/
	return;
    case EQ:
	rexpr(e1,l1,cond?"beq":"bne");
	return;
    case NEQ:
	rexpr(e1,l1,cond?"bne":"beq");
	return;
    case LAND:
	b_expr(e2,0,cond?(l2=fwdlabel()):l1);
	b_expr(caddr(e1),cond,l1);
	if(cond) fwddef(l2);
	return;
    case LOR:
	b_expr(e2,1,cond?l1:(l2=fwdlabel()));
	b_expr(caddr(e1),cond,l1);
	if(!cond) fwddef(l2);
	return;
    case CRGVAR:
	/*printf("\tcmpb $0,%s\n",caddr(e1));*/
	jcond(l1,cond);
	return;
    case CRLVAR:
	/*printf("\tcmpb $0,%d($fp)\n",lvar(e2));*/
	jcond(l1,cond);
	return;
    case RGVAR:
	/*printf("\tcmpl $0,%s\n",caddr(e1));*/
	jcond(l1,cond);
	return;
    case RLVAR:
	/*printf("\tlw \t%s,%d($fp)\n",crn,lvar(e2));*/
	jcond(l1,cond);
	return;
    case REGISTER:
	/*printf("\tcmpl $0,%s\n",register_name(e2));*/
	jcond(l1,cond);
	return;
    case CONST:
	if((cond&&e2)||(!cond&&!e2)) jmp(l1);
	return;
    default:
	g_expr(e1);
	/*printf("\tcmpl $0,%s\n",crn);*/
	jcond(l1,cond);
	return;
    }
}

void
ascii(char *s)
{
    printf("\t.ascii \"");
    while(*s) {
	if (*s=='\n')
	    printf("%cn",92);
	else if (*s<' ')
	    printf("%c%03o",92,*s);
	else if (*s==34)
	    printf("%c%c",92,34);
	else 
	    printf("%c",*s);
	s++;
    }
    printf("%c\n",34);
}

void
string(int e1)
{
    char *s;
    int i,lb;

    if (0) {
	s=(char *)cadr(e1);
	printf("\t.rdata\n");
	printf("\t.align\t2\n");
	lb=fwdlabel();
	printf("\tj\t$L%d\n",lb);
	i=backdef();
	ascii(s);
	printf("\t.align 2\n");
	fwddef(lb);
	printf("\tla\t%s,$L%d\n",crn,i);
    } else {
	s=(char *)cadr(e1);
        printf("\t.rdata\n");
	printf("\t.align\t2\n");
	lb=fwdlabel();
	printf("$L%d:\n",lb);
	ascii(s);
	if (output_mode==TEXT_EMIT_MODE) {
	    printf("\t.text\n");
	} else {
	    text_mode();
	}
	printf("\tla\t%s,$L%d\n",crn,lb);
    }
}

void
function(int e1)
{
    int e2,e3,e4,e5,nargs;
    NMTBL *n;

    e2 = cadr(e1);
    nargs = 0;
    for (e3 = caddr(e1); e3; e3 = cadr(e3)) {	
	n=(NMTBL *)(e5=(cadr(e4 = car(e3))));
	switch(car(e4)){
	case FNAME:
	    printf("\tlw\t%s,0(%s)\n",crn,n->nm);
	    break;
	case ADDRESS:
	    g_expr(e5);
	    break;
	default:g_expr(e4);
        }
	++nargs;
    }
    if (car(e2) == FNAME) {	
	n=(NMTBL *)cadr(e2);
	use_register(creg,REG_04,0);
	printf("\tjal\t%s\n",n->nm);
    } else {	
	g_expr(e2);
	use_register(creg,REG_04,0);
	printf("\tjal\t*%s\n",crn);
    }
    /*if (nargs) printf("\taddl $%d,%%esp\n",size_of_int*nargs);*/
}

int
arg_size(int e3,int *nargs0)
{
    int i,nargs,offset_list,e,t;

    offset_list = 0;
    /* we should use prototypes's type */
    for (i = nargs = 0; e3;e3 =cadr(e3)) {
	e = car(e3); t = caddr(e3);
	if (i < MAX_REGISTER_VAR && scalar(t)) {
	     offset_list = list3(-(REG_05+i++),offset_list,e);
	} else {
	    offset_list = 
	       list3(nargs,offset_list,e);
	    nargs += (car(e3)==CHAR?size_of_int:size(t));
	}
    }
    *nargs0 = -nargs;
    return offset_list;
}

void
jump(int e1, int env)
{
    int i,args,e2,e3,e4,e5,nargs,nargs0,regs;
    NMTBL *n,*code0;
    int new_disp,scode,disp1;
    char *xrn;

    /* We need three passes. Compute Stack size, Compute Arg, Copy it. */
    /* count number of args */
    args = caddr(e1);
    args = reverse0(args);
    nargs = arg_size(args,&new_disp);  /* compute in normal order */
    disp1 = (fnptr->sc==CODE)?0:-size_of_int;
    if (new_disp+disp1 < disp) {  /* have to extend stack */
	if (fnptr->sc==CODE)
	    printf("\tlw\t$sp,%d($fp)\n",new_disp-size_of_int);
	else
	    printf("\tlw\t$sp,%d($fp)\n",new_disp+disp_offset);
    }
    /* compute jump address */
    e2 = cadr(e1);
    if (car(e2) == FNAME) {	
	code0=(NMTBL *)cadr(e2);
	if (code0->sc!=CODE) {
	    error(STERR); return;
	}
    } else {	/* indirect */
	g_expr(e2);
	emit_push();
    }
    /* compute arguments in reverse order */
    regs = 0;
    i=MAX_REGISTER_VAR;
    for (e3=nargs; e3;e3 =cadr(e3)) {
	n=(NMTBL *)(e5=(cadr(e4 = caddr(e3))));
	switch(car(e4)) {
	case FNAME:
	    printf("\tlw\t%s,0(%s)\n",crn,n->nm);
	    emit_push();
	    break;
	case ADDRESS:
	    g_expr(e5);
	    emit_push();
	    break;
	case RLVAR:
	case CRLVAR:
	    if (env==0 && fnptr->sc==CODE) {
		if (e5>=0 && e5==car(e3)) {
		/* The same positioned local variable. No need to copy */
		    reg_stack[reg_sp++] = -2;
		}
		break;
	    }
	    g_expr(e4);
	    emit_push();
	    break;
	case REGISTER:
	    if (i>0 && rname[e5]==REG_05+ --i) {
		/* The same register variable. No need to copy */
		reg_stack[reg_sp++] = e5;
		break;
	    }
	default:
	    g_expr(e4);
	    emit_push();
	}
	regs++;
    }
    if (env) {
	/* change the frame pointer */
	g_expr(env);
	printf("\tmove\t%s,$fp\n",crn);
    } else if (fnptr->sc==FUNCTION) {
	printf("\tlw\t$fp,%d($fp)\n",disp_offset);
    } 
    /* force lvar offset mode to CODE */
    scode = fnptr->sc; fnptr->sc = CODE;
    /* copy arguments to destination environment if necessary */
    nargs = reverse0(nargs); /* pop in normal order */
    i=0;
    for (e3=nargs; e3;e3 =cadr(e3)) {
	if ((e4=car(e3))<0)  {
	    /* register case */
	    if (reg_stack[--reg_sp]>=REG_05) {
		/* the same registger */
	    } else {
		if(reg_stack[reg_sp]<0) {
		    /*printf("\tpopl %s\n",reg_name[rname[REG_05+i]]);*/ /* e4? */
		} else {
		    printf("\tmove\t%s,%s\n",
			    reg_name[rname[REG_05+i]],
			    reg_name[rname[reg_stack[reg_sp]]]); /* e4? */
		    free_register(reg_stack[reg_sp]);
		}
		i++;
	    }
	} else {
	    /* local variable case */
	    if (reg_stack[reg_sp-1]== -2) {
		/* same positioned variable */
		reg_sp--;
	    } else {
		xrn=emit_pop(0);
		printf("\tlw\t%s,%d($fp)\n",xrn, lvar(e4));
	    }
	}
    }
    if (car(e2) != FNAME) {	
	xrn=emit_pop(0);
    }
    if (!env && new_disp+disp1>disp) {
	/* shrink stack if necessary */
	printf("\tlw\t$sp,%d($fp)\n",new_disp-size_of_int);
    } 
    if (car(e2) == FNAME) {	
	printf("\tj\t%s\n",code0->nm);
    } else {
	printf("\tj\t*%s\n",xrn);
    }
    fnptr->sc = scode;
}


void
machinop(int e1)
{
    int e2,e3,op;

    e2 = cadr(e1);
    op = car(e1);
    e3 = caddr(e1);
    g_expr(e3);
    emit_push();
    g_expr(e2);
    tosop(car(e1));
    return;
}


void
rindirect(int e1)   /* *(p +5 ) */
       
{
    char *op;
    int e2,e3,byte;

    op = ((byte = (car(e1) == CRINDIRECT)) ? "lb" : "lw");
    e3 = cadr(e2 = cadr(e1));
    g_expr(e2);
    printf("\t%s \t%s,%d(%s)\n",op,crn,lvar(e3),crn);
}

void
sassign(int e1)
{
    int e2,e3,e4,sz;
    char *xrn;

    e2 = cadr(e1);
    e3 = cadr(e2);
    e4 = caddr(e1);
    sz = size(cadr(e2));  /* cld rep movsb */
    g_expr(e4);
    emit_push();
    g_expr(e2);
    xrn = emit_pop(0);
    return;
}

void
assign(int e1)
{
    char *op;
    int e2,e3,e4,byte;
    char *xrn;

    op = ((byte=(car(e1) == CASS))? "sb" : "sw");
    /*    e2=e4 */
    e2 = cadr(e1);
    e3 = cadr(e2);
    e4 = caddr(e1);
    switch(car(e2)) {
    case GVAR:      /*   i=3 */
            g_expr(e4);
            /*if (byte) use_data_reg(creg,1);*/
            printf("\t%s \t%s,%s\n",op,crn,caddr(e2));
            return;
    case LVAR:
            g_expr(e4);
            /*if (byte) use_data_reg(creg,1);*/
            printf("\t%s \t%s,%d($fp)\n",op,crn,lvar(cadr(e2))*-1);
            return;
    case REGISTER:
            g_expr(e4);
	    if (creg!=cadr(e2))
		printf("\t%s \t%s,%s\n",op,crn,register_name(cadr(e2)));
            return;
    }
    g_expr(e4);
    emit_push();
    g_expr(e2);
    xrn = emit_pop(0);
    /*if (byte) use_data_reg(creg,1);*/
    printf("\t%s %s,(%s)\n",op,xrn,crn);
    printf("\tmove\t%s,%s\n",crn,xrn);
    return;
}

void
assop(int e1)
{
    int e2,e3,byte,op,new_reg;
    char *xrn;

    /*   e2 op= e3 */
    byte = (car(e1) == CASSOP);
    e2 = cadr(e1);
    if (car(e2)==INDIRECT) e2=cadr(e2);
    e3 = caddr(e1);
    op = cadddr(e1);

    g_expr(e3);
    emit_push();
    if (car(e2)==REGISTER) {
	new_reg=creg;
	set_crn(cadr(e2));
	tosop(op);
	set_crn(new_reg);
	printf("\tmove\t%s,%s\n",crn,register_name(cadr(e2)));
	return;
    }
    g_expr(e2);
    xrn = emit_pop(0);                           /* pop e3 value */
    /*printf("\tpushl %s   # assop \n",crn);*/      /* push e2 address */
    ld_indexx(byte,0,crn);
    new_reg = get_register();
    /* push e3 value */
    if(new_reg<0) {                     /* もうレジスタがない */
        reg_stack[reg_sp++] =  -1;
        /*printf("\tpushl %s\n",xrn);*/
    } else {
        reg_stack[reg_sp++] = xreg;     /* push するかわりにレジスタを使う */
    }
    tosop(op);
    if(new_reg>=0) free_register(new_reg);
    /*printf("\tpopl %s   # assop \n",drn);*/
    printf("\t%s\t%s,0(%s)\n",byte ? "lb" : "lw",crn,drn);
    return;

}


void
tosop(int op)
{
    int oreg;
    char *orn;

    oreg = pop_register();
    switch(op) {
    case LSHIFT:
    case ULSHIFT:
	shift("sall",oreg);
	return;
    case RSHIFT:
	shift("sarl",oreg);
	return;
    case URSHIFT:
	shift("shrl",oreg);
	return;
    }
    if(oreg==-1) {
	oreg = dreg;
    }
    orn = reg_name[rname[oreg]];
    switch(op) {
    case ADD:
	printf("\taddu \t%s,%s,%s\n",crn,crn,orn);
	return;
    case SUB:
	printf("\tsubu \t%s,%s,%s\n",crn,crn,orn);
	return;
    case BAND: 
	printf("\tand \t%s,%s,%s\n",crn,crn,orn);
	return;
    case EOR: 
	printf("\txor \t%s,%s,%s\n",crn,crn,orn);
	return;
    case BOR:
	printf("\tor \t%s,%s,%s\n",crn,crn,orn);
	return;
    case MUL:
    case UMUL:
	printf("\t%s\t%s,%s\n","mult",crn,orn);
	printf("\tmflo\t%s\n",crn);
	return;
    case DIV:
    case UDIV:
	if (op==DIV)
	    printf("\tdiv\t%s,%s,%s\n",crn,crn,orn);
	else 
	    printf("\txor\t%s,%s,%s\n\tdiv\t%s,%s,%s\n",crn,crn,orn,crn,crn,orn);
	return;
    case MOD:
    case UMOD:
        if (op==MOD)
	    printf("\trem\t%s,%s,%s\n",crn,crn,orn);
	else 
	    printf("\txor\t%s,%s,%s\n\tdiv\t%s,%s,%s\n",crn,crn,orn,crn,crn,orn);
	return;
    }
}

void
shift(char *op, int reg)
{
    if (reg>=0) {
	use_register(lreg,REG_03,1);
    } else {
	use_register(dreg,REG_03,0);
    }
    /*printf("\t%s %%cl,%s\n",op,crn);*/
}

void
ld_indexx(int byte, int n, char *xrn)
{	
    char *op;

    op = byte ? "lb" : "lw";
    if (n) 
	    printf("\t%s\t%s,%d(%s)\n",op,crn,n,xrn);
    else
	    printf("\t%s\t%s,0(%s)\n",op,crn,xrn);
}

void
st_indexx(int byte, int n, char *xrn)
{	
    char *op;

    op = byte ? "sb" : "sw";
    if (n) 
	    printf("\t%s\t%s,%d(%s)\n",op,crn,n,xrn);
    else
	    printf("\t%s\t%s,0(%s)\n",op,crn,xrn);
}

void
indexy(char *op, char *gvar)
{
    printf("\t%s %s,%s\n",op,crn,gvar);
}

void
cmpdimm(int e, int csreg)
{
    /* used in dosiwtch() */
    use_register(creg,csreg,0);
    /*printf("\tcmpl $%d,%s\n",e,crn);*/
}

void
opening(char *filename)
{
    printf("\t.file \t1 \"%s\"\n",filename);
    printf(" # GNU C 2.7.2.2 [AL 1.1, MM 40] Sony PlayStation compiled by GNU C\n\n");
    printf(" # Cc1 defaults:\n\n");
    printf(" # Cc1 arguments (-G value = 8, Cpu = 3000, ISA = 1):\n");
    printf(" # -msoft-float -quiet -dumpbase -o\n\n");
    printf(" # gcc2_compiled.:\n");
    printf(" # __gnu_compiled_c:\n");

    printf("\t.text\n");
    emit_init();
}

void
closing(void)
{
    global_table();
}

void
jmp_label(int l)
{
    printf("\tjmp\t_%d\n",l);
}

void
jmp_eq_label(int l)
{
     printf("\tj\t_%d\n",l);
}

void
rexpr(int e1, int l1, char *s)
{       
    g_expr(list3(SUB,cadr(e1),caddr(e1)));
    printf("\t%s\t%s,%s,$L%d\n",s,crn,crn,l1);
}

void
jcond(int l, char cond)
{       
    printf("\t%s\t%s,%s,$L%d\n",cond?"bne":"beq",crn,crn,l);
}

void
jmp(int l)
{       
    control=0;
    printf("\tj\t$L%d\n",l);
    /* align? */
}

int
fwdlabel(void)
{       
    return labelno++;
}

void
fwddef(int l)
{       
    control=1;
    printf("$L%d:\n",l);
}

int
backdef(void)
{       
    control=1;
    printf("$L%d:\n",labelno);
    return labelno++;
}

void
def_label(int cslabel, int dlabel)
{
    int fl;

    fl = 0;
    if (control) {
	jmp(fl=fwdlabel());
    }
    fwddef(cslabel);
    if (dlabel)
	jmp(dlabel);
    if (fl) {
	fwddef(fl);
    }
}

void
gen_comment(char *s)
{
     printf("# %s",s);
}

void
gen_source(char *s)
{
     printf("%s",s);
}

void
code_enter(char *name)
{
    printf("\t.align 4\n");
    if (stmode!=STATIC)
	printf(".globl %s\n",name);
    printf("\t.type\t%s,@function\n",name);
    printf("%s:\n",name);
}

void
code_enter1(int disp0,int args)
{
    if(disp0) {
	printf("\tsubl $%d,%%esp\n",-disp0);
    }
}

void
code_leave(char *name)
{
    local_table();
    printf("$L%d:\n",labelno);
    printf("\t.size\t%s,_%d-%s\n",name,labelno,name);
    labelno++;
}

void
enter(char *name, int disp)
{
    int a,b,i;
    a = b = 0;

    /*printf("\t.text\n");
    printf("\t.align \t2\n");
    if (stmode!=STATIC)
	printf("\t.globl \t%s\n",name);*/
    printf("%s:\n",name);

    printf("\t.frame \t$fp,%d,$31\n",-disp+save_reg*size_of_int);
    

    if(disp) a = 8;
    
    printf("\t.mask \t0x%d0000000,-8\n",a);
    printf("\t.fmask \t0x00000000,0\n");

    if(disp){
	printf("\tsubu \t$sp,$sp,%d\n",-disp+save_reg*size_of_int);
	printf("\tsw\t$31,%d($sp)\n",-disp+4*save_reg1);
	save_reg1--;
    }
    for(i=save_reg1;i==0;i--) {
        printf("\tsw\t$%d,%d($sp)\n",16+i,-disp+4*i);
    }

    /*if(strcmp("main",name))
	printf("\tjal \t%s_0\n",name);
    else 
	printf("\tjal \t__%s_0\n",name);*/

    printf("\tjal \t%s_0\n",name);

    printf("\t.end \t%s\n",name);
    printf("\t.sdata\n");
    printf("\t.align 2\n");

    save_reg = 0;
    save_reg1 = 0;
}

/* void
enter_no(char *name, int disp)
{

    printf("\t.align \t2\n");
    if (stmode!=STATIC)
    printf("\t.globl \t%s\n",name);

    printf("\t.ent \t%s\n",name);
    printf("%s_0:\n",name);
}

*/
void
enter1(int disp)
{
    if(disp) printf("\tsubu \t$sp,$sp,%d\n",-disp+save_reg*size_of_int);
    
}

void
leave(int control, char *name)
{
    int i;

    if (control)
	use_register(creg,REG_04,1);
    if (retcont) {
	if (control)
	    jmp(retlabel);
	fwddef(retcont);
	use_register(creg,REG_04,0);
	printf("\tmove\t%s,%s\n",crn,reg_name[REG_05]);
    }
    fwddef(retlabel);
    use_register(creg,REG_04,0);
    save_reg1 = save_reg;
    printf("\tmove\t$sp,$fp\n");

    printf("\tlw\t$31,%d($sp)\n",-disp+4*save_reg);
    save_reg--;
    for(i=save_reg;i==0;i--) {
	printf("\tlw\t$%d,%d($sp)\n",16+i,-disp+4*i);
    }


    if(disp) printf("\taddu \t$sp,$sp,%d\n",-disp+save_reg*size_of_int);  
    printf("\tj\t$31\n");

    local_table();
    printf("$L%d:\n",labelno);
    labelno++;
}


void
ret(void)
{       
    use_register(creg,REG_04,1);
    jmp(retlabel); 
}

void
gen_gdecl(char *n, int gpc)
{
    /*
    if (stmode!=STATIC)
	printf(".globl %s\n",n); 
     */
}

void 
align(int t)
{
    if (t!=CHAR) {
	if (data_alignment & 1)
	    printf("\t.align 2\n");
	data_alignment = 0;
    }
}

void
emit_data(int e, int t, NMTBL *n)
{
    int l;
    char *name;
    name = n->nm; 
    if(mode==GDECL)  { /* global */
	if (n->dsp != -1) {
	    n->dsp = -1;   /* initiallized flag */
	    printf(".globl\t%s\n",name);
	    data_mode(name);
	    align(t);
	    printf("%s:\n",name); 
	} else {
	    data_mode(0);
	}
        if(car(e)==CONST) {       
	    if (t==CHAR) {
		printf("\t.byte %d\n",cadr(e));
		if (data_alignment>0)
		    data_alignment++;
		gpc += 1;
	    } else {
		printf("\t.long %d\n",cadr(e));
		gpc += size_of_int;
	    }
        } else if(t!=CHAR) {       
	    gpc += size_of_int;
	    if(car(e)==ADDRESS&&car(cadr(e))==GVAR) {
		printf("\t.word %s\n",caddr(cadr(e)));
	    } else if(car(e)==FNAME) {
		printf("\t.word %s\n",((NMTBL *)cadr(e))->nm);
            } else if(car(e)==STRING) {       
		if (car(n->ty)!=ARRAY || cadr(n->ty)!=CHAR) {
		    l = fwdlabel();
		    printf("\t.word _%d\n",l);
		    printf("$L%d:\n",l);
		    output_mode = RODATA_EMIT_MODE;
		}
		ascii((char *)cadr(e));
	    } else error(TYERR);
        }
    } else {
	/* if (n->sc!=LVAR) { error(TYERR); return; } */
        if(car(e)==CONST) {       
		printf("\tmove\t%s,%d\n",crn,cadr(e));
		printf("\t%s\t%s,%d($fp)\n",t==CHAR?"lb":"lw",crn,n->dsp);
        } else if(t!=CHAR) {       
		if(car(e)==ADDRESS&&car(cadr(e))==GVAR)
		    printf("\tlw\t%s,0(%s)\n",crn,caddr(e));
                else if(car(e)==FNAME)
		    printf("\tlw\t%s,0(%s)\n",crn,((NMTBL *)cadr(e))->nm);
		else if(car(e)==STRING) {       
		    string(e);
                } else error(TYERR);
		printf("\tlw\t%s,%d($fp)\n",crn,n->dsp);
        }
    }
}

void
emit_data_closing(NMTBL *n)
{
    int lb;
    if (mode=GDECL) {
	data_mode(0);
	lb=fwdlabel();
	printf("$L%d:\n",lb);
	printf("\t.size\t%s,_%d-%s\n",n->nm,lb,n->nm);
    }
}

void
global_table(void)
{
    NMTBL *n;
    for(n=ntable;n < &ntable[GSYMS];n++) {
	if (n->sc == GVAR && n->dsp != -1) {
	    /* n->dsp = -1 means initialized global */
	    printf("\n\t.comm \t%s,%d\n",n->nm,size(n->ty));
	}
    }
}

void
local_table(void)
{
    NMTBL *n;
    /* static local variables */
    for(n=ntable+GSYMS;n < &ntable[GSYMS+LSYMS];n++) {
	if (n->sc == GVAR) {
	    printf(".lcomm %s,%d\n",n->nm,size(n->ty));
	}
    }
}

void
text_mode(void)
{
    if (output_mode!=TEXT_EMIT_MODE) {
	printf(".text\n");
	printf("\t.align 2\n");
	output_mode = TEXT_EMIT_MODE;
    }
}

void
data_mode(char *name)
{
    if (output_mode!=DATA_EMIT_MODE) {
	printf(".data\n");
	output_mode = DATA_EMIT_MODE;
    }
    if (name)
	printf("\t.type\t%s,@object\n",name);
}

int
lvar(int l)
{
    if (l<0) {
	if (fnptr->sc==CODE)
	    return l+code_disp_offset;
	else
	    return l+disp_offset;
    } else {
	if (fnptr->sc==CODE)
	    return -l+code_arg_offset;
	else
	    return l+arg_offset;
    }
}

/* end */